Underwater vehicle

ABSTRACT

A vehicular frame submerged in a body of water is heavier than the water it displaces. The frame has a chamber with an open side adjacent to the bottom of the body of water. Water is supplied to the chamber at a pressure sufficiently higher than the ambient water outside the chamber to support the weight of the submerged frame; the supplied water escapes slowly from the chamber between the open side of the frame and the bottom of the body of water. The frame is moved across the bottom of the body of water while its weight is supported by water pressure in the chamber.

United States Patent [191 Anders [11] 3,902,440 -4 1 Sept. 2, 1975 [73] Assignee: Global Marine Inc., Los Angeles,

Calif.

22 Filed: Jan. 28, 1974 21 Appl.No.: 437,131

[56] References Cited UNITED STATES PATENTS 3,380,256 4/1968 Rebikoff 61/46.5 3,520,381 7/1970 Pinder Frankel 1 14/230 3,811,583 5/1974 Weeks 180/127 Primary Examiner-Trygve M. Blix Assistant Examiner-Gregory W. OConner Attorney, Agent, or FirmChristie, Parker & Hale [57] ABSTRACT A vehicular frame submerged in a body of water is heavier than the water it displaces. The frame has a chamber with an open side adjacent to the bottom of the body of water. Water is supplied to the chamber at a pressure sufficiently higher than the ambient water outside the chamber to support the weight of the submerged frame; the supplied water escapes slowly from the chamber between the open side of the frame and the bottom of the body of water. The frame is moved across the bottom of the body of water while its weight is supported by water pressure in the chamber.

19 Claims, 2 Drawing Figures UNDERWATER VEHICLE BACKGROUND OF THE INVENTION This invention relates to an underwater vehicle for moving along the bottom of a body of water.

In ocean mining and exploratory activities, there is a need for underwater vehicles capable of traveling along the bottom of the ocean. A wheeled vehicle encounters difficulty under some circumstances because of the softness of the ocean bottom.

SUMMARY OF THE INVENTION According to the invention, a vehicular frame submerged in water has a chamber with an open side adjacent to the bottom of the body of water. Preferably, the chamber is defined by a load supporting platform and a flexible skirt extending downwardly from the platform. The frame is heavier than the water it displaces. Water is supplied to the chamber under sufficient pressure to support the weight of the submerged frame; the supplied water escapes slowly from the chamber between the open side of the frame and the bottomrof the body of water. The frame is moved along the bottom of the water while it is held up by water pressure in the chamber. No difficulty is encountered in regions where the bottom is soft because the weight of the frame is distributed evenly over the entire area adjacent to the bottom.

In one embodiment, the frame is towed by a ship at the water surface; water is supplied to the chamber through an umbilical connected to a pump on board the ship. In another embodiment, the underwater vehicle is self-propelled and self-contained; operation is controlled from a ship on the water surface via acoustical signals.

BRIEF DESCRIPTION OF THE DRAWINGS The features of specific embodiments of the best mode contemplated of carrying out the invention are illustrated in the drawings, in which:

FIG. 1 is a partially schematic diagram of one embodiment of an underwater vehicle incorporating the principles of the invention; and

FIG. 2 is a partially schematic diagram of another embodiment of an underwater vehicle incorporating the principles of the invention.

DETAILED DESCRIPTION OF THE SPECIFIC EMBODIMENTS In FIG. 1, a vehicular frame is shown in cross section. Frame 10 is submerged in the ocean near its bot tom, designated 11. Frame 10 comprises a substantially planar load supporting platform 12 and a flexible skirt 13, which extends downwardly from platform 12 to bottom 11. Skirt 13 may be of the type used in air cushion vehicles and may be made of rubber or rubberized fabric of a type resistant to salt water. Skirt 13 extends completely around the perimeter of platform 12 to define with platform 12 and bottom 11 a plenum chamber. A cargo 16 may be carried on platform 12.

The described underwater vehicle is serviced by a self-powered tender 17 at the water surface. A pump 18 on board tender 17 is connected by an umbilical l9, i.e., a conduit, to the plenum chamber. Pump 18 supplies water at an increased pressure to the plenum chamber. Alternatively, pump 18 could be carried by frame 10 and connected to tender 17 by an electrical power carrying umbilical, if the water depth is great. The pressure difference between the water inside the plenum chamber and the ambient water outside the plenum chamber is sufficiently large in view of the area of platform 12 and the resultant submerged weight of frame 10, including its cargo 16 to support frame 10 with platform 12 in closely spaced relationship from bottom 11, as shown in the drawings. Generally. a pressure difference of 0.5 to 1.0 psi would be suitable. The flexibility of skirt 13 causes its lower edge to conform to bottom 11, thereby minimizing the amount of water that escapes from the plenum chamber. Pump 18 is preferably a variable speed propeller type axial flow pump.

Frame 10 is towed by tender 17. A tow line 20 of conventional construction is connected between frame 10 and tender 17 for this purpose.

The submerged weight of frame 10 could be controlled by buoyancy tanks. The: term submerged weight is used to mean the difference between the resultant weight of frame 10 and the weight of the water frame 10 displaces. The objective is to maintain the resultant submerged weight of frame 10 and cargo 16 at a value only slightly larger than the weight of the water they re place, irrespective of the amount and density of the cargo, so the pressure difference between the water inside the plenum chamber and the ambient water outside the plenum chamber does not have to be too great.

Before pump 18 is actuated, platform 12 rests on bottom 11. After pump 18 is actuated to rotate at high RPM. platform 12 begins to rise as water is pumped into the plenum chamber. Platform l2 rises to a point where skirt 13 is lifted off bottom 11, and pressure in the plenum chamber drops, and platform 12 falls until skirt 13 touches bottom 11 again. This vertical oscillation continues until the speed of pump 18 is downwardly adjusted to a point where the position of platform 12 is stabilized. Motion sensors could be employed to determine when this. has occurred. The adjustment is performed by an operator on tender 17 who monitors the sensors and changes the speed setting of pump 18 accordingly. It has been discovered that exceptionally good stability results in an aqueous medium, vis-a-vis, air.

In FIG. 2, a self-propelled and self-contained embodiment is disclosed. The same reference numerals are employed to identify elements in common with the embodiment in FIG. 1. An energy source 25, a pump 26, a pump 27, a buoyancy tank 28, and a motor 29 are secured to the top of platform 12 where they are enclosed in a housing 30. Cargo 16 is carried on housing 30. Pump 26, which is energized by source 25, is connected to the plenum chamber. Pump 18 supplies to the plenum chamber ambient water at an increased pressure. Element 33 represents that pump 26 has an adjustable speed. Source 25 also energizes motor 29 which drives a propeller 34 to move frame 10 through the water while platform 12 is supported by the water pressure in the plenum chamber. Appropriate means designated by element 35 for controlling motor 29 to regulate the speed and direction of frame 10 would also be provided.

Buoyancy tank 28 permits the submerged weight of frame 10 to be controlled. Pump 27 which is also energized by source 25, replaces water in tank 28 with compressed gas to reduce the submerged weight of frame 10 when cargo 16 increases, and replaces the compressed gas with water to increase the submerged weight when cargo 16 decreases. Pump 27 is operated by controls designated by element 32.

Energy source 25 could comprise a battery or nuclear generator. The power transmitting connections are represented in the drawing by heavy lines.

Pump 26, pump 27, and motor 29 are controlled from tender 17 on the water surface by acoustical signals propagating through the water between an acoustical antenna 36 under tender l7 and an acoustical antenna 37 on frame 10. Motion sensors 38 on frame 10 could communicate with tender 17 in the same manner. Alternatively, communication for the control function could be through an umbilical. The control transmitting connections are represented in the drawing by light lines.

Before pump 18 is actuated, platform 12 rests on bottom 11. The initial adjustment to raise platform 12 off of bottom 11 is either performed by an automatic control system on frame 10 responsive to sensors 38, or by an operator on tender 17, who monitors sensors 38 and signals an appropriate speed setting to pump 26 via the communication link.

The described embodiments of the invention are only considered to be preferred and illustrative of the inventive concept; the scope of the invention is not to be restricted to such embodiments. Various and numerous other arrangements may be devised by one skilled in the art without departing from the spirit and scope of this invention. Particularly, the vehicular frame could take any number of different configurations, and the plenum chamber could be formed in other ways. The nature of the skirt, i.e., flexible or segmented, depends upon the surface characteristics of the bottom of the body of water. If the bottom is relatively smooth, a continuous skirt may be employed. The described vehicle could be used for any number of purposes, including load carrying and dredging. v

In some cases, the position of cargo 16 must be adjusted to balance the torque applied by tow line 20 to frame 10; otherwise tow line 20 may lift the front of frame 10 higher than the back thereof.

What is claimed is:

1. An underwater vehicle for moving along the bottom of a body of water, the vehicle comprising:

a load supporting platform which is submersible for supporting a submerged load on the bottom of a body of water and for moving the load thereacross;

flexible skirt means extending downwardly from the platform to define with the platform and the bottom of the body of water a plenum chamber;

means operable when the platform is submerged for pumping into the plenum chamber water at a pressure sufficiently higher than the ambient pressure outside the plenum chamber to support the platform, the pumped water escaping slowly from the chamber between the skirt means and the bottom of the body of water; and

means for moving the platform across the bottom of the body of water while the platform is supported by operation of the pumping means.

2. The vehicle of claim 1, in which the pumping means is a variable speed pump adjusted in speed to stabilize the vertical position of the platform.

3. The vehicle of claim 2, additionally comprising a buoyancy chamber attached to the platform, means for admitting ambient water to the buoyancy chamber, and

means for pumping water from the buoyancy chamber.

4. The vehicle of claim 1. in which the moving means comprises a ship at the surface of the water and means connected between the ship and the platform for towing the platform.

5. The vehicle of claim 4, in which the pumping means comprises a pump on board a ship at the surface of the water and an umbilical connecting the pump to the chamber.

6. The vehicle of claim 1, in which the pumping means comprises a pump on board a ship at the surface of the water and an umbilical connecting the pump to the chamber.

7. A vehicle for moving along the bottom of a body of water, the vehicle comprising:

a vehicular frame submerged in the water;

a load supported by the frame in the water, the resultant weight of the load and the frame being larger than the weight of the water they displace so the weight of the frame and the load draw the frame and the load toward the bottom of the body of water;

means in the frame defining a chamber having an open side adjacent to the bottom of the body of water; and

means for supplying to the chamber liquid under sufficient pressure to support the weight of the submerged frame and hold the frame in closely spaced relationship from the bottom of the body of water.

8. The vehicle of claim 7, additionally comprising means for moving the frame along the bottom of the body of water.

9. The vehicle of claim 7, additionally comprising means for adjusting the flow of fluid supplied to the chamber.

10. The vehicle of claim 7, in which the frame comprises a load carrying platform on which the cargo lies and flexible skirt means extending downwardly from the platform toward the bottom of the body of water and the defining means comprises the inside surface of the platform and the inside surface of the skirt means.

11. The vehicle of claim 8, wherein the means for moving the frame is a self-powered vessel and means for mechanically connecting the vessel to the frame to pull the frame.

12. The vehicle of claim 8, wherein the means for moving the frame is carried by the frame and is operable to self-propel the frame.

13. The vehicle of claim 7, wherein the means for supplying includes a pump having an inlet connected to receive water from outside the chamber and an outlet connected to discharge water to the chamber, and means for powering the pump.

14. The vehicle of claim 13, in which the pump is carried by the frame.

15. The vehicle of claim 13, in which the pump is carried on board a service vessel and the outlet of the pump is connected to the chamber by a conduit.

16. A method for moving a load across the bottom of a body of water comprising the steps of:

a. Submerging to the bottom of the body of water a load-supporting platform having a flexible skirt means extending downwardly therefrom to define with the platform and the bottom of the body of water a substantially enclosed'space;

said pressure to the space. 17. The method of claim 16, wherein the liquid is water obtained from adjacent the exterior of the space. 18. The method of claim 16, in which the moving step comprises towing the platform with a surface vessel.

19. The method of claim 18, in which the supplying step supplies water from surface of the body of water. 

1. An underwater vehicle for moving along the bottom of a body of water, the vehicle comprising: a load supporting platform which is submersible for supporting a submerged load on the bottom of a body of water and for moving the load thereacross; flexible skirt means extending downwardly from the platform to define with the platform and the bottom of the body of water a plenum chamber; means operable when the platform is submerged for pumping into the plenum chamber water at a pressure sufficiently higher than the ambient pressure outside the plenum chamber to support the platform, the pumped water escaping slowly from the chamber between the skirt means and the bottom of the body of water; and means for moving the platform across the bottom of the body of water while the platform is supported by operation of the pumping means.
 2. The vehicle of claim 1, in which the pumping means is a variable speed pump adjusted in speed to stabilize the vertical position of the platform.
 3. The vehicle of claim 2, additionally comprising a buoyancy chamber attached to the platform, means for admitting ambient water to the buoyancy chamber, and means for pumping water from the buoyancy chamber.
 4. The vebicle of claim 1, in which the moving means comprises a ship at the surface of the water and means connected between the ship and the platform for towing the platform.
 5. The vehicle of claim 4, in which the pumping means comprises a pump on board a ship at the surface of the water and an umbilical connecting the pump to the chamber.
 6. The vehicle of claim 1, in which the pumping means comprises a pump on board a ship at the surface of the water and an umbilical connecting the pump to the chamber.
 7. A vehicle for moving along the bottom of a body of water, the vehicle comprising: a vehicular frame submerged in the water; a load supported by the frame in the water, the resultant weight of the load and the frame being larger than the weight of the water they displace so the weight of the frame and the load draw the frame and the load toward the bottom of the body of water; means in the frame defining a chamber having an open side adjacent to the bottom of the body of water; and means for supplyinG to the chamber liquid under sufficient pressure to support the weight of the submerged frame and hold the frame in closely spaced relationship from the bottom of the body of water.
 8. The vehicle of claim 7, additionally comprising means for moving the frame along the bottom of the body of water.
 9. The vehicle of claim 7, additionally comprising means for adjusting the flow of fluid supplied to the chamber.
 10. The vehicle of claim 7, in which the frame comprises a load carrying platform on which the cargo lies and flexible skirt means extending downwardly from the platform toward the bottom of the body of water and the defining means comprises the inside surface of the platform and the inside surface of the skirt means.
 11. The vehicle of claim 8, wherein the means for moving the frame is a self-powered vessel and means for mechanically connecting the vessel to the frame to pull the frame.
 12. The vehicle of claim 8, wherein the means for moving the frame is carried by the frame and is operable to self-propel the frame.
 13. The vehicle of claim 7, wherein the means for supplying includes a pump having an inlet connected to receive water from outside the chamber and an outlet connected to discharge water to the chamber, and means for powering the pump.
 14. The vehicle of claim 13, in which the pump is carried by the frame.
 15. The vehicle of claim 13, in which the pump is carried on board a service vessel and the outlet of the pump is connected to the chamber by a conduit.
 16. A method for moving a load across the bottom of a body of water comprising the steps of: a. Submerging to the bottom of the body of water a load-supporting platform having a flexible skirt means extending downwardly therefrom to define with the platform and the bottom of the body of water a substantially enclosed space; b. disposing the load to be moved on the platform, the combination of the load and the platform being negatively buoyant; c. supplying to the space a liquid under pressure sufficiently greater than ambient pressure at the platform to support the platform, with the load disposed thereon, in spaced relation to the bottom of the body of water; and d. moving the platform across the bottom of the body of water while continuing to supply liquid under said pressure to the space.
 17. The method of claim 16, wherein the liquid is water obtained from adjacent the exterior of the space.
 18. The method of claim 16, in which the moving step comprises towing the platform with a surface vessel.
 19. The method of claim 18, in which the supplying step supplies water from surface of the body of water. 